Pan Jia-Bin, Yang Zhi-Chun, Zhang Xuan-Ge, Li Mao-Lin, Zhou Qi-Lin
State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Frontiers Science Center for New Organic Matter, Nankai University, Tianjin, 300071, China.
Angew Chem Int Ed Engl. 2023 Sep 25;62(39):e202308122. doi: 10.1002/anie.202308122. Epub 2023 Aug 21.
The enantioselective addition of potent nucleophiles to ketenes poses challenges due to competing background reactions and poor stereocontrol. Herein, we present a method for enantioselective phosphoric acid catalyzed amination of ketenes generated from α-aryl-α-diazoketones. Upon exposure to visible light, the diazoketones undergo Wolff rearrangement to generate ketenes. The phosphoric acid not only accelerates ketene capture by amines to form a single configuration of aminoenol intermediates but also promotes an enantioselective proton-transfer reaction of the intermediates to yield the products. Mechanistic studies elucidated the reaction pathway and explained how the catalyst expedited the transformation and controlled the enantioselectivity.
由于存在竞争性背景反应和立体控制不佳的问题，向烯酮中对映选择性地添加强亲核试剂具有挑战性。在此，我们提出了一种对映选择性磷酸催化由α-芳基-α-重氮酮生成的烯酮胺化反应的方法。在可见光照射下，重氮酮发生沃尔夫重排生成烯酮。磷酸不仅加速胺对烯酮的捕获以形成单一构型的氨基烯醇中间体，还促进中间体的对映选择性质子转移反应以生成产物。机理研究阐明了反应途径，并解释了催化剂如何加速转化并控制对映选择性。
